Hi, On Tue, May 24, 2016 at 3:47 PM, Luca Barbato <lu_z...@gentoo.org> wrote:
> On 23/05/16 17:01, Ronald S. Bultje wrote: > > Howdy, > > Interesting. I spent a bit of time on it myself. > > I run some benchmark using a yuv422 file of the right size from the > Tim's collection [directly][1] and looped/cut to have a length that > works fine (1minute and 10 minutes) and I used `perf stat -r 30` on a > system that surely has a cpu unencumbered by random process on a server, > so it does not have random quirks like a laptop one. > > The benchmark shown that force-inlining bitstream_read_vlc is not > exactly helpful on the poor constained x86_32, and its implementation > could spare few branches. > > With that change in, looks like the gains for x86_64 get even larger. > > I get the dnxhd to be about 3% slower on x86_32 and 20% faster on x86_64. [..] > And with that I guess we are set =) But 2 out of 3 are still slower. I can try to look somewhat more into this, but I think that not understanding what makes it slower is fundamentally flawed. If we understand why it's slower and we decide that that's OK, that's an entirely different thing. Ronald _______________________________________________ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
